[time-nuts] GPS Time to Year?

Hal Murray hmurray at megapathdsl.net
Thu Jan 22 19:52:14 EST 2009


A nice list.  Thanks.

> One may even know the date&time well before the first GPS signal lock.

Be careful with that one.

Time is used for all sorts of things, some critical and some mostly a 
convenience.

Time is often central in network security.  That often turns into an 
interesting tangle.  How do you securely set the time when your security 
stuff doesn't work yet because you don't know the time?

Anyway, setting the time depending on the time that you already "know" has 
similar problems.  It's probably a good approach, but may not be good enough. 
 Where did you get that time from?  Somebody has to think about the big 
picture and the costs/risks of getting it wrong.


Another place where you can get a sanity check on the time is from the file 
system.

If you are running an embedded application out of ROM/Flash or off a CD, 
that's the time of manufacturer.  If you are running on an OS, it's probably 
the time some file was recently written, but that assumes the system time was 
correct.



-- 
These are my opinions, not necessarily my employer's.  I hate spam.







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